Commonly, relatively massive railroad boxcar bulkheads or load dividers are employed to restrain cargo from shifting around within the boxcar during transit. Each bulkhead consists of one or more large panels the approximate size of a boxcar's transverse cross-section. Each bulkhead is positioned transversely within a railroad boxcar and pivotally carried by overhead tracks for movement longitudinally within the boxcar. The bulkhead has a mechanism for releasably locking it in position to prevent the cargo from shifting during transport.
To unload, load and secure cargo, the bulkheads must be moved. Previously, workers would unlock and manually pull or push the heavy bulkhead into position. Frequently, one worker would unlock the bulkhead while another would assist in moving it by pushing or pulling one edge of the bulkhead with their fingers precariously positioned in the narrow space between the bulkhead and the inner wall of the boxcar. Not infrequently, strained backs and pinched fingers have resulted from sudden forward and/or lateral skewing movement of the freely pivoting bulkhead. Feet can also be nipped if the bulkhead unexpectedly swings toward the worker.
An unlocked bulkhead can also be moved by manual rotation of a loop of an overhead pull chain. However, if the door lurches in either direction, the chain can grab and injure the fingers of the operator. Feet can also be nipped if the bulkhead unexpectedly swings toward the worker. Moreover, this pull chain is cumbersome and often not used.